From the JLR in Jacksonville this morning. I'll try a visit tomorrow, after I finish some business in Brunswick --

"Mr. Hargrove,
I’ve been working closely with our shop foreman to determine the best way to assist you. Unfortunately, due to the way our schematics are structured, we’re unable to search by specific areas of the vehicle—they’re organized by fault codes or individual components.
Given the varying readings you’re seeing, it’s unlikely these are ground wires, it is more likely they are black by design for security purposes. To provide accurate wiring schematics, we’ll need to identify the specific component involved. Once that’s traced, we’ll be able to supply the relevant documentation.
Service Manager
Jaguar Land Rover Jacksonville"

 

FYI, I posted links in the currently 2nd thread on the forum. I have wiring diagrams and schematics, but they’re in a broken html hierarchy. Makes it quite hard to find anything. But the wiring reference gives the # of pins in a connector, the color, size and function of each wire, what tools are needed to work on the connector, etc.

I copied this from the other thread…

I turns out I have a lot of info, but unfortunately, the electrical reference and schematics use an HTML hierarchy and all the links are broken. But with enough motivation, you can work through individual files or perhaps search the folder for keywords. There’s also a workshop manual in there, but I think with the same broken links.
https://www.dropbox.com/scl/fo/3o2g1...=vdrocs3e&dl=0

 

I went through the connectors in the headliner instruments and marked them as best as I could. Some go back to the front pillar, and some to the rear. Perhaps I'll have enough information accumulated to match most of them.

I'm concerned mostly about the three 'oddballs'--the one with the 3v bleed, and the two that show a straight ground when the other end of the ohmmeter is hooked to a bolt in the roof. The other five can probably be traced back to a connector.

Anyway, we'll see if the Jag dealership can add to the understanding... or confusion.

 

I looked through those, and the few I pulled up appear to be out of the Jag shop manual (a copy of which I found and bought online). There are over 6000 pages. Discussions with the Jag dealer in JAX indicate they can do nothing without fault codes. Well, and good; however, the car is obviously immobile.

It seems, also, that some of the wiring is deliberately unmarked, for what they called "security" reasons. Go figure...

Looks like I'll have to pair wires to find out where they go back to...

 

Can't you check continuity from the side going to the fuse box and the fuse box so that you at least know one side of the problem???

 

Okay, we're closing in on the same page.

I popped the trim off the passenger pillow, and pulled the main connector there (a green one, which takes the harness down to the fuse boxes below). I've ID'd all the pins inside the connector and marked all the wires coming from it to the cut wires inside the car. Now, I'm looking for a way to match the cut wires coming from the upper console to that side of the cut. So, I know where these wired need to go.

The issue now is finding continuity from the wires coming from the upper console to the wiring connector. Thus far, I've been trying jumpers between a marked wire and its black wire in different connectors in the upper console. This is to find continuity within one of the connectors. If I have continuity, I will have a pairing. If I can do that, I can start ID'ing pairs, and transfer that knowledge to the wires/pins going back into the main connector in the pillar.

I've only tried a couple today, and ran out of time. I'll try different console connector pairings tomorrow.

 

Also (and maybe a dumb question at this point) --

Ground wires go to a grounding terminal, and not to a fusebox. Correct?

 

I think that is true (I assume relays, which are often in fuse boxes, are grounded within the box).

Once you get this fixed, you owe your wife a nice dinner for all the cursing you have been doing! lol

 

Today, I'm running continuity between everything I can get at, to understand the grounding system. If I can trace pins 1 & 2 (the oddballs) and 16 & 17 (the pure grounds), I think that'll be a big step in figuring out this mess. Probably still will have to get behind a couple of fuse boxes, to check from the closest grounding terminals.

You're right... she keeps asking,

The green block is the female connector running down to the other half in the passenger pillar.

What I'm coming up with thus far. Be nice to know the pillar matches for the two 'bookends'...
"Where's my car?" LOL

 

Unfortunately, I’m not sure you can assume all grounds go to body studs. Power grounds, probably yes. But there may be communication grounds or signal returns that would continue to the destination connector. Hard to know without knowing what the signals are. I think it’s a good assumption that if the wire is a larger gauge, then going to a stud is probably right as it’s designed to carry some current.

 

What I sent the Jaguar dealership last night...


... and its reply this morning --

 

Analysis

I was looking at the main connector in pillar all weekend, trying to draw parallels between it, the values I got from it, and the information from Jaguar. Test my conclusions for me—

1. The main connector has 22 pin locations, with numbers (Going by my ID), 4, 5, 6, 8, 9, 10, 11 being unused. That leaves 15 used pins NOTE: 21 & 22 were speaker wires, which were later identified and matched because of their ‘twisted pair’ appearance.

2. Of the 15, 7 have assigned values (wires are color-coded). That leaves 8 unidentified pins.

3. Of those 8 (NOTE: these values derived from the 22-pin connector at the pillar block, when the ohmmeter has been grounded to a structural stud in the cabin)–

a. #1 has a positive voltage (3.19v dc)

b. #2, 12, 13, 14, 15 all read .79 ohms

c. #16 & 17 read “0” ohms (pure grounds)

Now, examine the information from Jaguar/JAX, when asked about the all-black wires. The green connector block appears to be the “C39D” in question.

4. D-1 & D-2 (the telephone speaker in the upper console) can be easily identified because of the previously-mentioned markings. They correspond to pin 21 & 22 in the connector block.

5. Note that ALL of the others appear to be related to the telephonics in the upper console. Of these:

a. Two (#6 & 7) appear to be grounds for the system(s)

b. Four (#8, 9, 10 & 11) appear to be feeds for the LED lighting in the telephonics

c. One (#12) runs a call switch

d. One (#13) runs a diagnostic

Comparing the two sheets (and the values of the multimeter reads), it seems safe to assume that:

6. pin #s 16 & 17 would match to D-6 & D-7

7. pin #s 12, 13, 14, 15 would match to D-8, 9, 10, & 11

8. pin #s 1 & 2 would match back to D-12 & 13

Questions:

9. which one of D-12 or D-13 would need a 3+ volt dc feed, a switch or a diagnostic?

10. do all four of the LED lights have a common ground? (ie D-7)?

THOUGHTS?

​​​​​​​

 

You are definitely deeper into this and well beyond my ability to "have a clue" LOL

The question I have at this point is the 3.19v. Is the battery connected? I suppose (but again "no clue") if it is, it could be inductively coupled to the power in some way... Just a thought.

Best of luck!

 

Re: battery connected?

Good question, and thanks for the 'clue'.

Beginning at all this, I disconnected the "negative" terminal to do the work, and left the 'positive' attached. I'm pulling the battery shortly to charge it anyway(been sitting for a month), so it'll be a good time to see if the 'bleed' is coming from the red side. I'll check the #1 wire after I pull the battery--see if I get a different reading.

 

Inductive coupling doesn’t work that way. I believe you mentioned telematics - the telematics unit has its own battery for SOS and theft stuff, and I think it’s around 3V. So possibly related to that.

 

Thank you for that.

This seems to be all related to the upper console, which contains the SOS/security as well as other uses. The battery backup makes perfect sense.

FYI--I cranked the car yesterday, since it'd been almost a month, to let it warm up. I've noticed when trying to open the trunk with a key fob, I get a short 'toot', with no corresponding action from the trunk locking mechanism.

EDIT: Also, I revised the pin numbering to reflect what's indicated on the C39 block ---

 

Another discovery from yesterday...

 

I was able to match those black wires from the green connector block in the front-right pillar to the connector in the upper console. My only question is the D6/D7. Since they're both grounds, I'll have to have a code check done to see if they need to be swapped. Would have been nice to have the wires properly marked/identified by Jaguar, wouldn't it? Be even nicer if the headliner hadn't failed after nine years. Note to the unwary having to replace their headliner fabric--take off the trim on both pillars, and use the green disconnects. Save a lot of aggravation (and your wife's glares)...

 

Did you get this sorted? If you need help I can be of assistance with factory diagrams and info.

 

Well... mostly.

Got it all back together, and thinking I got everything on the passenger pillar matched. The driver's pillar had a handful of unmarked black wires as well, which I believe went to the SOS stuff in the upper console. Still getting "Limited Function" warning on it.
Took it to the Jag dealership in JAX last week. They ran diagnostics, found a burnt fuse and (they claim) a broken wire (wondering, since there are no wires exposed any more). Couldn't help with the last malfunction signal.

The biggest surprise from all this? You can't buy a replacement harness... anywhere. I was just going to do that, and use it for a repair pattern, or just pull the old harness off and replace it entirely. Not available. Two dealerships told me that. I'm writing Mahwah about it.

I'll probably spend time on it next year, depending on what JLR/Mahwah says about another harness...